Splash surface aerator

ABSTRACT

Apparatus and process for aerating a liquid by subjecting the surface of the liquid to the impingement of a body to cause the liquid in the area of impingement to splatter. Splattering substantially increases the gas-liquid interface of the liquid and facilitates absorption of gas in the liquid while requiring low power requirements. Apparatus and process of this invention are particularly useful for aerating water or sewage wastes to replenish oxygen or supply additional oxygen to aid in the breakdown of waste materials in aerobic systems.

Umted States Patent 1151 -3,685,8 1 0 Calcote 1 1 Aug. 22, 1972 SPLASHSURFACE AERATOR 1,275,583 1 8/1918 Mathys ..26l/81 72 I t Hart F "estCalcot P t 1,132,982 3/l915 Serrell l3 1 or 1,305,860 6/1919 Y ount..2s9/113 2,498,393 2/ 1950 Clewell ..25,9/ 1 1'3 1 Asslgnee= AeroChemResearch Laboratones, 1,653,321 12/1927 Swett .259/1 13 km 3,462,1328/1969 Kaelin ..26l/93 [22] Filed: Aug. 17, 1970 Primary Examiner-Tim R.Mlles [21] APPL 64,237 Assistant Examiner-Stven H. MarkowitzAttorney-Theodore B. Roessel [52] US. Cl. "261/81, 261/119, 259/113 I 511m. (:1. .1101: 3/04 1571 AB TRACT a Fleld of Search ..6l/l, 70, 1 12,App atu nd process aerating a ubject- 259/113 261ml 1 93 ing the surfaceof the liquid to. the impingement of a body to cause the liquid in thearea of impingement to [56] Reierences cued splatter. Splatteringsubstantially increases the gas- UNITED STATES PATENTS liquid i terface0f the liquid facilitates absorption of gas 1n the l1qu1d whlle requlrmglow power requlre- Dlcketman et a1. ments Apparatus and process ofinvention are GOSS useful for aerating water or ewage wastes 1,632,9436/ 1927 Beebe ..259/1 12 to replenish oxygen or Supply additional oxygento aid 1 19,898 10/ l87l NlChOlS et a] ..259/ 1 12 in the breakdown ofwaste materials i aerobic 107 ,443 9/ 1870 Bullock ..25 9/ l 12 systems1,452,097 4/1923 Ross ..259/1 12 425,645 4/1890 White ..259/1 13 8Claims, 9 Drawing figures PATENT EI M1322 I97? 3 6 85 8 l O sum 1 or 2INVENTORS HARTWELL F. CALCOTE ATTORNEY sum 2 BF 2 ll llll INVENTORS'HARTWELL F CALCOTE ATTORNEY SPLASH SURFACE AERATOR This inventionrelates to apparatus for introducing a gas or a mixture of gases into aliquid.

BACKGROUND OF THE INVENTION A major technique used in the treatment ofwater, sewage waste and the like, is the introduction of oxygen into thewater or sewage waste to replenish oxygen or to supply additional oxygento aid the breakdown of waste materials in aerobic systems. Theatmosphere generally provides the oxygen source and the technique forintroducing atmospheric oxygen into the water involves, with very fewexceptions, the rotation of an impeller type device which causes thefluid to move at a great volocity. The main objective is to maximize thewater-gas interface through which oxygen can be transported from theatmosphere to the liquid. Such techniques involve the use of largeamounts of power for the pounds of oxygen per horsepower hour absorbedin the liquid. Generally speaking, such high consumptions of power aredue to the fact that large volumes of water must be moved at relativelyhigh velocities in order to achieve the necessary gas-water interface.Moreover, such systems often require supplemental sources of oxygen inaddition to oxygen present in the atmosphere.

Accordingly, it is an object of this invention to provide apparatus toimproved gas introducing capacity per horsepower hour in order toincrease the efficiency and the economy of the operation.

Another object of this invention is to provide apparatus for introducinggas into liquid wherein there is provided at least one splasher head forstriking the liquid surface substantially perpendicularly thereto,thereby to form on and about the liquid surface, watergas interfacesthrough which the gas is introduced into the liquid.

These and other objects and advantages of this invention will becomeapparent upon consideration of the following detailed description andthe drawings and the novel features thereof will be particularly pointedout hereinafter in connection with the appended claims.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 shows a side elevation of anembodiment of apparatus represented schematically.

FIGS. 2A-2D illustrate various configurations of splasher heads inaccordance with this invention.

FIG. 3 shows a portion of the apparatus of FIG. 1 illustrating means forlimiting downward movement of the splasher head.

FIG. 4 illustrates schematically another embodiment of this inventionemploying an arm driven in a see-saw manner.

FIG. 5 illustrates yet another embodiment of this invention employing acrankshaft.

FIG. 6 illustrates an embodiment of this invention employing areciprocating solenoid or linear induction motor.

SUMMARY OF INVENTION I have discovered that unexpectedly high rates ofgas absorption in liquids are obtained when a body is impinged against aliquid surface with suflicient energy to displace and spatter thesurface liquid and thereby substantially increase the water-gasinterface of the spattered liquid for the absorption of surroundinggases in the spattered liquid. Repeated impingement on the liquidsurface by said body results in efficient gas absorption in the liquid.

The size and shape of the splasher will vary, depending upon the type ofdrive mechanism, the number of impacts per minute and the amount offorce imparted to the splasher at the liquid surface. The drive meansfor effecting the raising and lowering of the splasher head may be ofany conventional type. Best results are obtained when the splasher head,impinges the liquid surface substantially perpendicularly thereto. Anysubstantial penetration of the splasher head under the liquid surfaceshould be avoided since raising the splasher head from under the surfacerequires undue amounts of energy and substantially reduces theefficiency of the process of the invention.

DESCRIPTION OF THE INVENTION Referring now to FIG. 1, there is shown inschematic form, an embodiment of this invention illustrating the basicprinciples thereof wherein a body of water 11, is aerated by thesubstantially perpendicular impingement of splasher head 12 on thesurface thereof. Splasher head 12 is carried by line 13 by way of pulley14 supported over said water surface by suitable means, not shown, towinch 16. Winch 16 is driven by suitable means such as for example,electric motor 17. Suitable clutch means are provided for winch 16 todisconnect winch 16 from motor 16 and to provide for the free-fall ofsplasher head 12 from its raised position as shown at 12a.

In operation, pulley 14, was positioned over the approximate center of atest basin having nominal dimensions of 15 feet in diameter by 4 feet indepth and containing 5,800 gallons of water. The pulley 14, wasapproximately 10 feet above the water surface. Line 13 was run fromwinch 16 through pulley 14 to splasher head 12. Splasher head 12 wasraised aknown distance by rotating winch 16 by means of motor 17 to aposition shown as broken lines at 12a. Release of the clutch meansallowed splasher head 12 to free-fall thereby to impinge on the watersurface substantially perpendicularly thereto. The length of line 13 wasselected so as to allow impingement of splasher head 12 on the watersurface in its downward position but prevented substantial penetrationof splasher head 12 under the water surface. After impact, splasher head12 was returned to its starting position 12a. For testing purposes thiscycle was repeated six times per minute for a total of 10 minutes.

To determine the rate of oxygen uptake in the water, dissolved oxygencontent was measured with a Yellow Springs Dissolved Oxygen Meter. Twodissolved oxygen measurement probes were located 8 inches below thesurface of the water and at a radial distance of 5 feet and 5.5 feetfrom the center of the test basin. Prior to beginning each test, thewater was de'oxygenated to about 1 part per million by the addition ofsodium sulfite and colbaltous chloride.

Referring to FIG. 2A, the splasher head was in the shape of an invertedcone, the side surfaces of which had a slight concavity. The splasherhead was weighted with sand to a total weight of 25 pounds. For thepurposes of this test, the splasher head had an axial dimension of 9inches and a maximum diameter of 19 inches.

A small mixer was operated during the tests to substantially uniformlydistribute dissolved oxygen throughout the test basin.

The rate of dissolved oxygen uptake (D.O. lb/hr.) was computed asfollows:

where y equals'oxygen uptake (ppm) fora given run and t equals time inhours.

Horsepower was determined according to the formula:

where w equals the weightofthe splasher, 1b., h equals the height abovesurface, ft., n equals total number of cycles and t equals time inhours.

9.6-10 -y Then, oxygen uptake efficlency 1n lb./Hp.-hr.= W

The results of the tests are set forth in Table I.

TABLE I Measured Oxygen Uptake Efficiency No. 7 Oxygen Splasher cyclesImpact Initial Final Oxygen Uptake 4 height (6 cycles velocity D0. D0.uptake eft'lc /min) t/ (pm) (pm) (pm) iency (lb/hP -hr 2 60 12 1.5 2.00.5 16 3 60 14 1.2 1.7 0.5 11 3 60 16 1.5 2.0 0.5 11 4 60 .16 1.7 2.40.7 11

The economy of the apparatus of this invention can be further increasedby storing that portion of the kinetic energy of the splasher which isin excess of the energy required to disperse and splatter the water atthe impact area. Furthermore, it is undesirable to have the splasherhead penetrate the water surface to any substantial depth since there islittle or no gas exchange brought about when the splasher head issubmerged beneath the water surface and the energy requirements to raisethe totally immersed splasher head substantially reduce the efficiencyof the operation Referring to FIG. 3, there is shown one'method forlimiting the downward travel of the splasher head and for utilizing.

excess kinetic energy to aid in returning the splasher head to itsraised position. Thereis shown a fragment of the apparatus shown in FIG.1 wherein splasher head 23 is attached to line 21 running from a poweredIn second series of tests, the splasher head shape was changedslightlyas shown in FIG. 2B and although the general configuration ofthe splasher head remained as an inverted cone, the side surfacesthereof were substantially straight line and the weight of the splasherwas increased to 31.5 lbs. As in the previous tests, all cycles were atthe ratejof 6 per minute. The results are set forth in Table II belowz'The average oxygen uptake efiiciency obtained in both tests was about 12lb/hp-hr.

Referring to FIG. 2C, there is shown another design for a splasher headwherein the head comprises a generally hejrnispheroidal shape. FIG. 2Dshows yet another embodiment of a splasher head wherein plate 18 isprovided with a multiplicity of perforations 19. It should be clear thatthe size and weight of the splasher head will be dependent upon thedrive mechanism, the number of cycles and the impact velocity.

winch, not shown, through pulley 22 for the raising of splasher head 23above the surface of the water 20 and for allowing the free fall thereofto the water surface. Splasher'head 23 is provided with an axial passage26 through which runs anchor cable 24. Anchor cable 24 may be carried bythe pulley support means, and suitably anchored on the shore. Whenanchor cable 24 is carried by the pulley support means, said supportmeans is suitably reinforced to absorb the shock of splasher head 23.Passage 26 is sufliciently large to allow for the free travel ofsplasher head '23 along anchor cable 24. Depending from anchor cable isplate 27 located beneath the surface of the water. Plate 27 is ofsufficient weight so as to maintain said anchor cable 24 in asubstantially vertical position. Spring 28 is carried by plate 27 and ispositioned thereon coaxially with anchor cable 24. Spring 28, in itsfully extended position, and plate '27, are located beneath the water toallow for the impingement of the water surface by splasher head 23while'at the same time making contact with'splasher head 23 to preventcomplete penetration of the water surface by splasher head 23.

In operation, splasher head 23 is raised by means of line 21 above thesurface ofwater 20. Splaslier head 23 is then allowed to free-fall toimpinge upon the water surface to effect the aeration thereof. Afterinitially impinging on the surface splasher head 23 contacts the upperend of spring 28 causing it to store the excess kinetic energy ofsplasher'head 23 as it is compressed by the downward travel of splasherhead 23. At the completion of the downward travel, splasher head 23 isthen withdrawn from the water and returned to a raised position, whichinitial withdrawal is assisted by the upward urging eflect of spring 28.

It should be clear that many treatment basins are substantially shallowand that, therefore, plate 27 can be readily carried by support meansresting on the bottom of the basin rather than by an anchor cable of thetype shown.

splasher head to spatter the water at'and'around the surface thereofthereby to the water-gas interface for the absorption of gas. Inaddition, more than one splasher head ma be employed in the apparatus ofthis invention.

Referring to FIG. 4, the apparatus is supported on the bottom of thelagoon by uprights 31 carrying platform 32. Pivoted on platform 32 isrocking arm 33 which carries at either end, splasher head 34 and 34.Rocking arm 33 is driven by conventional means such as rotary air motor35 to provide a see-saw motion to said arm 33 so that said splasherheads 34 and 34' alternately impinge upon the surface of the water. Thelength of each half of arm 33 is such that splasher head 34 and 34'impinge upon the water surface during the downward travel of therespective ends of arm 33 but do not substantially penetrate the watersurface. Sufiicient driving force is provided to raise one end andsplasher head of said arm while imparting energy to the downward movinghalf of said arm to effect splashing and resultant gas absorption. Ifdesired, suitable means may be provided, such as for example the typeillustrated in FIG. 3, for limiting the downward travel of heads 34 and34' and for urging heads 34 and 34 away from the water surface afterimpingement thereof by heads 34 and 34.

Referring to FIG. 5, there is shown partially in section, anotherembodiment of this invention wherein the apparatus is floating on abasin surface. Floats 41 and 41 are connected at their ends by framemember 42. Motor 43 is carried by float 41 for driving crankshaft 44which is journaled at its opposite end by journal bearing 45 carried byfloat 41'. Suitable transmission and fly-wheel means 46 are alsoprovided. Connecting rods 48 are carried by said crankshaft 44 by meansof bearings 49 and splasher heads 47 are connected to each of saidconnecting rods 48.

Although not shown, floats 41 and 41 may be provided with ballast meansfor adjusting the depth of penetration of splasher head 47 into thewater surface.

Referring to FIG. 6, there is shown a sectional schematic side elevationof another embodiment of this invention therein splasher head 51 isdriven by a reciprocating solenoid motor. The solenoids consists ofwindings 52 and 52' coaxially wound about shaft cylinder 53. Guide shaft54 having ferro-magnetic core 56 embedded therein, carries splasher head51. The upper end of shaft 54 terminates with plate 57. Shaft cylinder53 is of sufficient diameter to allow for the reciprocal travel of guideshaft 54 therethrough. In the embodiment shown, spring 58 is coaxiallypositioned in the upper end of shaft cylinder 53 in surroundingrelationship to shaft 54. Spring 58 is carried in shaft cylinder 53 byannular lip 59. Solenoid windings 52 are connected to a source ofcurrent through a conventional current reversal switch 61.

In operation the apparatus is positioned above the water and switch 61is set for causing current to flow through solenoid windings 52 causingiron core 56 to be urged upwardly causing guide shaft 54 and splasherhead 51 to travel upwardly. When splasher head 51 has been raised to adesired height above the water, switch 61 is activated to cause currentflow through the windings of the solenoid 52 and cause core 56, shaft 54and splasher head 51 to move in a downward direction. On completion ofthe downward stroke, plate 57 contacts spring 58 causing it to begin tocompress and to limit the downward travel of shaft 54 and splasher head51. Switch 61 is again activated to switch the current to solenoidwindings 52 thereby causing the upward movement of splasher head 51 awayfrom the water in the manner described above. In addition,

' spring 58 acting against plate 57- aids in reversing the Theforce-stroke characteristics of the solenoid motor are determined by thespacing, number and diameter of solenoid windings 52 and 52'. Theforcestroke characteristics may be altered by varying said spacing,number and diameter of said solenoid windings 52 and 52'.

While various driving means have been described, it should be clear thatreciprocal type driving means, such as for example-reciprocal air motorsand drive mechanisms of the type used in drilling apparatus, piledrivers and the like, may be used with equal success, it being importantonly that the driving means selected allow for the impingement on thewater surface of a body with sufiicient force to cause splattering ofthe water surface in area of impingement thereby to maximize thegas-liquid interface to facilitate the inclusion of gas in a liquid.

From the foregoing description, it is readily apparent how the presentinvention accomplishes its various objectives. While the invention hasbeen described and illustrated herewith, with reference to certainpreferred embodiments thereof, it is to be understood that it may beotherwise embodied within the scope of the appended claims.

I claim:

1. An aeration system comprising means confining a large body ofliquid'to be aerated, mechanical means supporting at least one splasherhead having an impinging surface above the surface of said liquid body,drive means for imparting reciprocal motion to said splasher head inimpinging relationship to said surface, and limiting means for limitingpenetration of said liquid surface by said splasher head and confiningsaid head to the vicinity of the liquid surface.

2. Apparatus of claim 1 wherein said limiting means is adapted forimparting reciprocal motion to said. splasher head after impingement ofa liquid surface thereby.

3. Apparatus of claim 1 wherein said splasher head is carried by a linerunning througha pulley supported above said liquid surfaceto a drivenwinch, said winch being provided with clutch means whereby said splasherhead may be raised above said liquid surface Y and released to impingethereon thereby to effect aeration of said liquid.

4. Apparatus of claim 3 wherein spring means are provided for contactingsaid splasher head after impingement by said splasher head of saidwater. surface thereby to limit complete penetration of said surface bysaid splasher head and to urge said splasher head inareciprocaldirection.

5. Apparatus of claim 1 wherein a splasher head is carried at each endof a beam supported substantially at its center so that each of saidsplasher heads carried by each end is in impinging relationship to saidliquid surface and driving means is provided for driving said beam in asee-saw motion whereby reciprocal motion is imparted to each of saidsplasher heads for impingement thereof on said liquid surface.

6. Apparatus of claim l'wherein said splasher head is carried inimpinging relationship to said liquid surface a by a crankshaft wherebyrotation of said crankshaft imparts reciprocal motion to said splasherhead.

7. The apparatus ,of claim 6 wherein a plurality of splasher heads arecarried by said crankshaft.

8. Theapparatus of claim 1 wherein saidudriving means comprises a sourceof current, at least two solenoids, a shaft, carrying said splasherhead, reciprocally, coaxially positioned in impinging relationship tosaid liquid surface within said solenoids, said shaft containsaidsolenoids imparts reciprocal motion to said sh carrying said splasherhead.

1. An aeration system comprising means confining a large body of liquidto be aerated, mechanical means supporting at least one splasher headhaving an impinging surface above the surface of said liquid body, drivemeans for imparting reciprocal motion to said splasher head in impingingrelationship to said surface, and limiting means for limitingpenetration of said liquid surface by said splasher head and confiningsaid head to the vicinity of the liquid surface.
 2. Apparatus of claim 1wherein said limiting means is adapted for imparting reciprocal motionto said splasher head after impingement of a liquid surface thereby. 3.Apparatus of claim 1 wherein said splasher head is carried by a linerunning through a pulley supported above said liquid surface to a drivenwinch, said winch being provided with clutch means whereby said splasherhead may be raised above said liquid surface and released to impingethereon thereby to effect aeration of said liquid.
 4. Apparatus of claim3 wherein spring means are provided for contacting said splasher headafter impingement by said splasher head of said water surface thereby tolimit complete penetration of said surface by said splasher head and tourge said splasher head in a reciprocal direction.
 5. Apparatus of claim1 wherein a splasher head is carried at each end of a beam supportedsubstantially at its center so that each of said splasher heads carriedby each end is in impinging relationship to said liquid surface anddriving means is provided for driving said beam in a see-saw motionwhereby reciprocal motion is imparted to each of said splasher heads forimpingement thereof on said liquid surface.
 6. Apparatus of claim 1wherein said splasher head is carried in impinging relationship to saidliquid surface by a crankshaft whereby rotation of said crankshaftimparts reciprocal motion to said splasher head.
 7. The apparatus ofclaim 6 wherein a plurality of splasher heads are carried by saidcrankshaft.
 8. The apparatus of claim 1 wherein said driving meanscomprises a source of current, at least two solenoids, a shaft, carryingsaid splasher head, reciprocally, coaxially positioned in impingingrelationship to said liquid surface within said solenoids, said shaftcontaining a core responsive to the polarity of a magnetic field createdby the flow of current through said solenoids and means for switchingcurrent flow between said solenoids whereby alternating current flowbetween said solenoids imparts reciprocal motion to said shaft carryingsaid splasher head.